Sacral nerve neuromodulation improves physical, psychological and social quality of life in patients with fecal incontinence

Could nerve transplantation be the future of this field: a bibliometric analysis about lumbosacral plexus injury

BACKGROUND

Lumbosacral plexus injury is a highly distressing clinical issue with profound implications for patients' quality of life. Since the publication of the first relevant study in 1953, there has been very limited progress in basic research and clinical treatment in this field, and the developmental trajectory and research priorities in this field have not been systematically summarized using scientific methods, leaving the future direction of this research to be explored.

METHODS

Utilizing publications from the Web of Science (WoS) database, our research employed bibliometric methodology to analyze the fundamental components of publications, synthesize research trends, and forecast future directions.

RESULTS

A total of 150 publications were included in our study, and the impressive advancement of research heat in this field can be attributed to the continuous increase in the number of papers, ranging from 14 papers in 2000 to 34 papers in 2023 over five years. Regarding the country, a central position in both quantity (H-index=125) and quality of publications (65 publications) is occupied by the United States, and close collaborations with other countries are observed. In terms of publication institutions, the highest number of publications (9 publications) is held by the Second Military Medical University. The journal with the most publications (5 publications) is the Journal of Trauma-Injury Infection and Critical Care. A pivotal role has been played by basic medical research in the development of this field. Concerning hotspots, the focus of the research core can be divided into three clusters (etiology, diagnosis and treatment; molecular, cells and mechanisms; physiology and pathology).

CONCLUSION

This marks the inaugural bibliometric analysis of lumbosacral plexus injuries, offering a comprehensive overview of current publications. Our findings illuminate future research directions, international collaborations, and interdisciplinary relationships. Future research will emphasize clinical treatment and mechanism research, with a focus on sacral nerve stimulation and nerve transplantation.

Improvements in Self-Reported Depression Following Treatment of Fecal Incontinence with Sacral Neuromodulation

OBJECTIVE

To evaluate changes in self-reported depression after treatment of fecal incontinence (FI) with sacral neuromodulation.

MATERIALS AND METHODS

This is a subanalysis of data collected from March 2016 to October 2017 for an Institutional Review Board-approved retrospective cohort study. Demographic information, medical history, psychiatric comorbidities, and the Patient-Reported Outcomes Measurement Information System item bank t-scores were extracted from the electronic medical record. The differences in t-scores were compared with a two-sided paired t-test, and a p value <0.05 was considered statistically significant.

RESULTS

Of the cohort (n = 24), most were Caucasian (88%), female (92%), nonsmokers (92%). Median age was 63.5 years (interquartile range 57.5-71.0 years) and median body mass index was 27.7 kg/m² (range 18.3-42.9 kg/m² ). A significant decrease in mean depression t-scores occurred after implantation of a sacral neuromodulation device, -4.5 (95% confidence interval [CI]: -8.7, -0.2, p = 0.04). Self-reported pain interference (p = 0.37) and physical function (p = 0.47) scores were similar following implantation. Individuals with comorbid anxiety reported the greatest improvement in depression (-6.5, 95% CI: -11.8, -1.1, p = 0.02).

CONCLUSIONS

Treatment of FI with sacral neuromodulation was associated with improvement in self-reported depression with the greatest improvement in those with anxiety. Further prospective research is needed to corroborate these findings.

Functional segregation within the pelvic nerve of male rats: a meso- and microscopic analysis

The pelvic splanchnic nerves are essential for pelvic organ function and have been proposed as targets for neuromodulation. We have focused on the rodent homologue of these nerves, the pelvic nerves. Our goal was to define within the pelvic nerve the projections of organ-specific sensory axons labelled by microinjection of neural tracer (cholera toxin, subunit B) into the bladder, urethra or rectum. We also examined the location of peptidergic sensory axons within the pelvic nerves to determine whether they aggregated separately from sacral preganglionic and paravertebral sympathetic postganglionic axons travelling in the same nerve. To address these aims, microscopy was performed on the major pelvic ganglion (MPG) with attached pelvic nerves, microdissected from young adult male Sprague-Dawley rats (6-8 weeks old) and processed as whole mounts for fluorescence immunohistochemistry. The pelvic nerves were typically composed of five discrete fascicles. Each fascicle contained peptidergic sensory, cholinergic preganglionic and noradrenergic postganglionic axons. Sensory axons innervating the lower urinary tract (LUT) consistently projected in specific fascicles within the pelvic nerves, whereas sensory axons innervating the rectum projected in a complementary group of fascicles. These discrete aggregations of organ-specific sensory projections could be followed along the full length of the pelvic nerves. From the junction of the pelvic nerve with the MPG, sensory axons immunoreactive for calcitonin gene-related peptide (CGRP) showed several distinct patterns of projection: some projected directly to the cavernous nerve, others projected directly across the surface of the MPG to the accessory nerves and a third class entered the MPG, encircling specific cholinergic neurons projecting to the LUT. A subpopulation of preganglionic inputs to noradrenergic MPG neurons also showed CGRP immunoreactivity. Together, these studies reveal new molecular and structural features of the pelvic nerves and suggest functional targets of sensory nerves in the MPG. These anatomical data will facilitate the design of experimental bioengineering strategies to specifically modulate each axon class.

Outcomes of Implementation of Sacral Nerve Stimulation in Incontinent Patients in Shiraz

BACKGROUND

Fecal incontinence is a common disorder in old age; however, it may not threaten life, but it can cause morbidity and many problems. Sacral nerve stimulation (SNS) is a minimally invasive surgical procedure performed by chronic electrical stimulation of the nerves in the sacral plexus through a lead implanted at the S3 foramen. This study aimed to evaluate the outcomes of SNS in Shiraz.

MATERIALS AND METHODS

Data from patients who underwent implantation of an SNS device from 2012 to 2018 were reviewed in Shiraz. Thirty patients who had incontinence were evaluated by a committee. Pre- and postoperative assessments of the severity of incontinence were performed using Wexner Incontinence Score. Statistical analysis was performed using paired t-test.

RESULTS

Twenty-seven patients proceeded to insertion in the temporary SNS, and of these, 16 were elected to have a permanent SNS. Finally, seven patients were satisfied with their treatment. There was a significant reduction in the pre- and post-SNS Wexner Incontinence Scores from a median of 15-10, respectively (P < 0.05).

CONCLUSION

In our study, 16 patients underwent SNS protocol, and 43.7% of them showed a good response and recovered. It is recommended as a method for the treatment of fecal incontinence. Permanent SNS is effective, showing a significant improvement in fecal incontinence scores.

Systematic review of the impact of sacral neuromodulation on clinical symptoms and gastrointestinal physiology

Background

Sacral neuromodulation (SNM) has emerged as a treatment option for faecal incontinence (FI). However, its objective effect on symptoms and anorectal function is inconsistently described. This study aimed to systematically review the impact of SNM on clinical symptoms and gastrointestinal physiology in patients with FI, including factors that may predict treatment outcome.

Methods

An electronic search of MEDLINE (1946–2014)/EMBASE database was performed in accordance with PRISMA guidelines. Articles that reported the relevant outcome measures following SNM were included. Clinical outcomes evaluated included: frequency of FI episodes, FI severity score and success rates. Its impact on anorectal and gastrointestinal physiology was also evaluated.

Results

Of 554 citations identified, data were extracted from 81 eligible studies. Meta‐analysis of the data was precluded due to lack of a comparison group in most studies. After permanent SNM, ‘perfect’ continence was noted in 13–88% of patients. Most studies reported a reduction in weekly FI episodes (median difference of the mean −7.0 (range: −24.8 to −2.7)) and Wexner scores (median difference of the mean −9 (−14.9 to −6)). A trend towards improved resting and squeeze anal pressures and a reduction in rectal sensory volumes were noted. Studies failed to identify any consistent impact on other physiological parameters or clinicophysiological factors associated with success.

Conclusion

SNM improves clinical symptoms and reduces number of incontinence episodes and severity scores in patients with FI, in part by improving anorectal physiological function. However, intervention studies with standardized outcome measures and physiological techniques are required to robustly assess the physiological impact of SNM.

Sacral nerve stimulation for faecal incontinence and constipation: a European consensus statement

AIM

In Europe during the last decade sacral nerve stimulation (SNS) or sacral neuromodulation (SNM) has been used to treat faecal incontinence (FI) and constipation. Despite this, there is little consensus on baseline investigations, patient selection and operative technique. A modified Delphi process was conducted to seek consensus on the current practice of SNS/SNM for FI and constipation.

METHOD

A systematic literature search of SNS for FI and constipation was conducted using PubMed. A set of questions derived from the search and expert opinion were answered on-line on two occasions by an international panel of specialists from Europe. A 1-day face-to-face meeting of the experts finalized the discussion.

RESULTS

Three hundred and ninety-three articles were identified from the literature search, of which 147 fulfilled the inclusion criteria. Twenty-two specialists in FI and constipation from Europe participated. Agreement was achieved on 43 (86%) of 50 domains including the set-up of service, patient selection, baseline investigations, operative technique and programming of the device. The median of agreement was 95% (35-100%).

CONCLUSION

Consensus was achieved on the majority of domains of SNS/SNM for FI and constipation. This should serve as a benchmark for safe and quality practice of SNS/SNM in Europe.

A systematic review of sacral nerve stimulation mechanisms in the treatment of fecal incontinence and constipation

BACKGROUND

Sacral nerve stimulation (SNS) is now well established as a treatment for fecal incontinence (FI) resistant to conservative measures and may also have utility in the management of chronic constipation; however, mechanism of action is not fully understood. End organ effects of SNS have been studied in both clinical and experimental settings, but interpretation is difficult due to the multitude of techniques used and heterogeneity of reported findings. The aim of this study was to systematically review available evidence on the mechanisms of SNS in the treatment of FI and constipation.

METHODS

Two systematic reviews of the literature (performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses framework) were performed to identify manuscripts pertaining to (a) clinical and (b) physiological effects of SNS during the management of hindgut dysfunction.

KEY RESULTS

The clinical literature search revealed 161 articles, of which 53 were deemed suitable for analysis. The experimental literature search revealed 43 articles, of which nine were deemed suitable for analysis. These studies reported results of investigative techniques examining changes in cortical, gastrointestinal, colonic, rectal, and anal function.

CONCLUSIONS & INFERENCES

The initial hypothesis that the mechanism of SNS was primarily peripheral motor neurostimulation is not supported by the majority of recent studies. Due to the large body of evidence demonstrating effects outside of the anorectum, it appears likely that the influence of SNS on anorectal function occurs at a pelvic afferent or central level.

Sacral neuromodulation and peripheral nerve stimulation in patients with anal incontinence: an overview of techniques, complications and troubleshooting

Sacral neuromodulation (SNM) therapy has revolutionized the management of many forms of anal incontinence, with an expanded use and a medium-term efficacy of 75% overall. This review discusses the technique of SNM therapy, along with its complications and troubleshooting and a discussion of the early data pertaining to peripheral posterior tibial nerve stimulation in incontinent patients. Future work needs to define the predictive factors for neurostimulatory success, along with the likely mechanisms of action of their therapeutic action.

Current status: new technologies for the treatment of patients with fecal incontinence

Fecal incontinence is a frequent and debilitating condition that may result from a multitude of different causes. Treatment is often challenging and needs to be individualized. During the last several years, new technologies have been developed, and others are emerging from clinical trials to commercialization. Although their specific roles in the management of fecal incontinence have not yet been completely defined, surgeons have access to them and patients may request them. The purpose of this project is to put into perspective, for both the patient and the practitioner, the relative positions of new and emerging technologies in order to propose a treatment algorithm.

Sacral nerve stimulation for fecal incontinence improves symptoms, quality of life and patients' satisfaction: results of a monocentric series of 119 patients

PURPOSE

Sacral nerve stimulation (SNS) is validated as an efficient treatment for fecal incontinence (FI). However, long-term results are scarce in the literature. The goal of this study was to assess the impact of SNS on FI symptoms and quality of life, based on a retrospective analysis of prospectively collected data.

METHODS

From 2001 to 2009, 119 patients (six men, mean age 61 years) underwent SNS testing for FI after an extensive diagnostic workup. Permanent implantation was realized when FI symptoms improved during testing, and follow-up visits were performed every 12 months thereafter. This follow-up evaluated morbidity and efficacy, based on clinical data and self-administered questionnaires including Jorge and Wexner FI score, urinary incontinence score (urinary distress inventory-6, UDI-6), gastrointestinal quality of life index (GIQLI), and auto-evaluation scale.

RESULTS

A permanent stimulator was implanted after a positive test in 102 patients (91 %). Ten patients were explanted during follow-up (pain in one case and absence of efficacy in nine), and 29 had the stimulator and/or the electrode changed. The mean follow-up was 48 months (range 12-84): there was a significant improvement of FI score (9 ± 1 vs 14 ± 3, p < 0.0001), UDI-6 score (8 ± 4 vs 11 ± 5, p < 0.05), and GIQLI index (p < 0.002). The improvement was present at 12 months follow-up and remained stable. Eighty percent of patients were satisfied with the treatment at the last point of follow-up. None of the pretreatment variables were predictive of SNS efficacy.

CONCLUSIONS

SNS improved FI and quality of life, and this efficacy remained over time. Although a complete disappearance of FI was rare, most patients were satisfied.

Postoperative issues of sacral nerve stimulation for fecal incontinence and constipation: a systematic literature review and treatment guideline

BACKGROUND

There is a lack of knowledge on the incidence and management of suboptimal therapeutic effect and the complications associated with sacral nerve stimulation for fecal incontinence and constipation.

OBJECTIVE

This study aimed to review current literature on postoperative issues and to propose a treatment algorithm.

DATA SOURCE

PubMed, MEDLINE, and EMBASE were searched using the keywords "sacral nerve stimulation," "sacral neuromodulation," "fecal incontinence," and "constipation" for English-language articles published from January 1980 to August 2010. A further search was conducted on a wider literature using the keywords "complication," "adverse effect," "treatment failure," "equipment failure," "infection," "foreign-body migration," "reoperation," "pain," and "algorithm."

STUDY SELECTION

Four hundred sixty-one titles were identified, and after a title and abstract review, 135 were subjected to full article review; 89 were finally included in this review. Five articles were added by manual search and consensus.

RESULTS

Forty-eight studies were identified as cohort studies reporting on postoperative issues, including 1661 patients who underwent percutaneous nerve evaluation and 1600 patients who proceeded to sacral nerve stimulation therapy. Pooled data showed that the most common problem during percutaneous nerve evaluation was lead displacement (5.3%). The incidence of suboptimal outcome, pain, and infection after implantation was 12.1%, 13.0%, and 3.9%.

LIMITATIONS

There was significant underreporting of untoward events, because 60% of the studies did not report complications during percutaneous nerve evaluation, and suboptimal outcome after implantation was not disclosed in 44% of the studies.

CONCLUSIONS

The incidence of untoward events associated with sacral nerve stimulation appears to be low. However, there is a significant underreporting of the incidence. Using the information from the structured and systematic literature review, we formulated a clinically relevant guideline for reporting and managing postoperative issues. The guideline can provide a framework for clinical practice.

Efficacy of sacral nerve stimulation for the treatment of fecal incontinence

BACKGROUND

Sacral nerve stimulation has been shown to be an effective treatment for fecal incontinence and early studies reported success rates of 67% to 100%. However, "success" has been arbitrarily set at a 50% reduction in symptoms, and data are rarely reported with "intention to treat."

OBJECTIVE

This study aimed to assess the true efficacy of sacral nerve stimulation for fecal incontinence compared with the published literature.

DESIGN

This prospective 5-year study was conducted to assess 50 patients with fecal incontinence treated with sacral nerve stimulation. All analyses were performed on an intention-to-treat basis.

SETTINGS

This study took place in a single tertiary referral colorectal department.

PATIENTS

Fifty consecutive patients with fecal incontinence refractory to conservative management were included in the study.

INTERVENTIONS

The interventions performed were temporary evaluation with or without permanent sacral nerve stimulation.

MAIN OUTCOME MEASURES

: Primary outcome measures were 1) attainment of continence, 2) reduction in fecal incontinence episodes, 3) improvement in Cleveland Clinic Fecal Incontinence scores, and 4) improvement in the ability to defer defecation.

RESULTS

Thirteen patients (26%) did not respond at the temporary evaluation stage or were dissatisfied with the result. Ten further patients (20%) did not achieve a 50% reduction in symptoms following permanent implantation. The median follow-up was 17 months (range, 2-55), at which time 27 patients (54%) experienced a 50% or more reduction in symptoms, including 13 (26%) who achieved apparent continence. Median fecal incontinence episodes per fortnight reduced from 14 (range, 0-53) to 2 (range, 0-20; P < .0001). Median Cleveland Clinic Fecal Incontinence scores reduced from 15 (range, 3-20) to 8 (range, 0-17; P < .0001). The ability to defer defecation improved significantly (P < .0001). These results compare favorably with the published literature.

LIMITATIONS

Quality of life was not assessed.

CONCLUSIONS

This study demonstrates that sacral nerve stimulation can be an effective treatment for patients with fecal incontinence; however, when analyzed by intention to treat, the symptoms of fecal incontinence continue in the majority (74%) of patients.

Long-term efficacy and safety of sacral nerve stimulation for fecal incontinence

BACKGROUND AND OBJECTIVE

Sacral nerve stimulation is effective in the treatment of urinary incontinence and is currently under Food and Drug Administration review in the United States for fecal incontinence. Previous reports have focused primarily on short-term results of sacral nerve stimulation for fecal incontinence. The present study reports the long-term effectiveness and safety of sacral nerve stimulation for fecal incontinence in a large prospective multicenter study.

DESIGN AND METHODS

Patients with fecal incontinent episodes more than twice per week were offered participation in this multicentered prospective trial. Patients showing ≥ 50% improvement during test stimulation were offered chronic implantation of the InterStim Therapy system (Medtronic; Minneapolis, MN). The aims of the current report were to provide 3-year follow-up data on patients from that study who underwent sacral nerve stimulation and were monitored under the rigors of an Food and Drug Administration-approved investigational protocol.

RESULTS

One hundred thirty-three patients underwent test stimulation with a 90% success rate, of whom 120 (110 females) with a mean age of 60.5 years and a mean duration of fecal incontinence of 7 years received chronic implantation. Mean length of follow-up was 3.1 (range, 0.2-6.1) years, with 83 patients completing all or part of the 3-year follow-up assessment. At 3 years follow-up, 86% of patients (P < .0001) reported ≥ 50% reduction in the number of incontinent episodes per week compared with baseline and the number of incontinent episodes per week decreased from a mean of 9.4 at baseline to 1.7. Perfect continence was achieved in 40% of subjects. The therapy also improved the fecal incontinence severity index. Sacral nerve stimulation had a positive impact on the quality of life, as evidenced by significant improvements in all 4 scales of the Fecal Incontinence Quality of Life instrument at 12, 24, and 36 months of follow-up. The most common device- or therapy-related adverse events through the mean 36 months of follow-up included implant site pain (28%), paresthesia (15%), change in the sensation of stimulation (12%), and infection (10%). There were no reported unanticipated adverse device effects associated with sacral nerve stimulation therapy.

CONCLUSIONS

Sacral nerve stimulation using InterStim Therapy is a safe and effective treatment for patients with fecal incontinence. These data support long-term safety and effectiveness to 36 months.

The influence of sacral nerve stimulation on gastrointestinal motor function in patients with fecal incontinence

BACKGROUND

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence of various etiologies. However, the mechanism of action remains unclear. The aim of the present study was to determine whether SNS affects gastric emptying, small intestinal transit or colonic transit times.

METHODS

Seven patients with a permanently implanted sacral nerve stimulator participated in a double-blind randomized cross-over study. The patients were allocated to stimulation ON or OFF for two 7-day periods separated by at least 1week. On days 4-7 of each 7-day period, the patients were examined by gamma camera imaging to measure gastric emptying, small intestinal transit and colonic transit parameters of a radiolabeled, 1600 kJ mixed solid and liquid meal ingested on day 4.

KEY RESULTS

Sacral nerve stimulation did not change gastric retention at 15 min, gastric mean emptying time, gastric half emptying time, small intestinal mean transit time or colonic geometric center after 24, 48 and 72 h.

CONCLUSIONS & INFERENCES

  Sacral nerve stimulation does not induce major changes in the propulsive capacity of the gastrointestinal tract in patients successfully treated for fecal incontinence with permanent sacral nerve stimulator.

The influence of sacral nerve stimulation on anorectal dysfunction

AIM

Sacral nerve stimulation (SNS) has become an established option in the management of defaecatory disorders. There are many data on the end-organ effects of SNS, but limited consensus on its mechanism of action. The objective of this review was to determine the effect of sacral nerve stimulation (SNS) on anorectal function.

METHOD

Systematic literature review of the effect of sacral nerve stimulation (SNS) on anorectal function.

RESULTS

There was significant heterogeneity of data pertaining to the effects of SNS on anorectal function, with no consistent change in physiological measures identified. Most data supported a mixed mechanism of action on anal motor and rectal sensory functioning.

CONCLUSION

To date, conflicting data exist on the mechanism of action of SNS as determined by end-organ changes in anorectal physiology. Nevertheless, the data as they stand best support a mixed mechanism of action on anal motor and rectal sensory functions.

Meta-analysis: sacral nerve stimulation versus conservative therapy in the treatment of faecal incontinence

AIM

Sacral nerve stimulation (SNS) has recently been used in the management of faecal incontinence (FI). This study compared SNS to conservative management with regards to functional and quality of life outcomes.

METHODS

Meta-analysis of studies published between 1995 and 2008 on SNS for FI was performed. Outcomes evaluated were functional, physiological and quality of life. A random-effects model was used and sensitivity analyses performed. Subgroup analyses were performed on age and sphincter status.

RESULTS

Thirty-four studies were included, reporting on 944 patients undergoing peripheral nerve evaluation; 665 underwent permanent SNS. Weekly incontinence episodes (weighted mean difference [WMD] -6.83; 95% confidence intervals [CI] -8.05, -5.60; p < 0.001) and incontinence scores (WMD -10.57; 95% CI -11.89, -9.24; p < 0.001) were significantly reduced with SNS; ability to defer defecation (WMD 7.99 min; 95% CI 5.93, 10.05; p < 0.001) was increased. Most SF-36 and FIQL domains improved following SNS, and mean anal pressures increased significantly (p < 0.001). Results remained consistent on sensitivity analysis. The under-56 years age group showed smaller functional but greater physiological and quality of life improvements. Results were similar between sphincter intact and impaired subgroups. The complication rate was 15% for permanent SNS, with 3% resulting in permanent explantation.

CONCLUSION

SNS results in significant improvements in objective and subjective measures for faecally incontinent patients.

Poor outcome of sphincter repair: an evacuation problem?

INTRODUCTION

Colorectal transport in idiopathic fecal incontinence has scarcely been studied, and it remains to be investigated in patients with fecal incontinence and anal sphincter lesion. The aim of the present study was to compare colorectal transport during defecation in patients with idiopathic fecal incontinence and patients with fecal incontinence due to anal sphincter lesions with transport in healthy volunteers.

METHOD

Five women with idiopathic fecal incontinence (median age 72 years, range: 58-78 years) and five women with an obstetric sphincter lesion (median age 42 years, range: 28-63 years), four of whom had had previous anal sphincter repair, were compared with nine healthy female volunteers (median age 53 years, range 32-57 years). Colorectal scintigraphy was performed to assess colorectal emptying at defecation as well as segmental antegrade and retrograde transport during defecation. Segmental colorectal transit times were determined using radio-opaque markers.

RESULTS

Median colorectal emptying time at defecation was significantly lower in the sphincter lesion group compared with the healthy volunteers (P = 0.009). At defecation, median antegrade transport time from the ascending colon was significantly lower in the sphincter lesion group than in the healthy group (P = 0.02). The median segmental transit time from the rectosigmoid colon was higher in the group with a sphincter lesion than in the healthy group (P = 0.05). There were no statistically significant differences between the group with idiopathic fecal incontinence and the healthy volunteers.

CONCLUSION

Patients with fecal incontinence due to sphincter lesions, but not those with idiopathic fecal incontinence, have reduced transport from the cecum/ascending colon and from the rectosigmoid colon at defecation.

Sacral nerve stimulation for treatment of intractable pain associated with cauda equina syndrome

Sacral nerve stimulation (SNS) is an effective treatment for bladder and bowel dysfunction, and also has a role in the treatment of chronic pelvic pain. We report two cases of intractable pain associated with cauda equina syndrome (CES) that were treated successfully by SNS. The first patient suffered from intractable pelvic pain with urinary incontinence and fecal incontinence after surgery for a herniated lumbar disc. The second patient underwent surgery for treatment of a burst fracture and developed intractable pelvic area pain, right leg pain, excessive urinary frequency, urinary incontinence, voiding difficulty and constipation one year after surgery. A SNS trial was performed on both patients. Both patients' pain was significantly improved and urinary symptoms were much relieved. Neuromodulation of the sacral nerves is an effective treatment for idiopathic urinary frequency, urgency, and urge incontinence. Sacral neuromodulation has also been used to control various forms of pelvic pain. Although the mechanism of action of neuromodulation remains unexplained, numerous clinical success reports suggest that it is a therapy with efficacy and durability. From the results of our research, we believe that SNS can be a safe and effective option for the treatment of intractable pelvic pain with incomplete CES.

Sacral nerve stimulation for fecal incontinence: results of a 120-patient prospective multicenter study

BACKGROUND

Sacral nerve stimulation has been approved for use in treating urinary incontinence in the United States since 1997, and in Europe for both urinary and fecal incontinence (FI) since 1994. The purpose of this study was to determine the safety and efficacy of sacral nerve stimulation in a large population under the rigors of Food and Drug Administration-approved investigational protocol.

METHODS

Candidates for SNS who provided informed consent were enrolled in this Institutional Review Board-approved multicentered prospective trial. Patients showing > or =50% improvement during test stimulation received chronic implantation of the InterStim Therapy (Medtronic; Minneapolis, MN). The primary efficacy objective was to demonstrate that > or =50% of subjects would achieve therapeutic success, defined as > or =50% reduction of incontinent episodes per week at 12 months compared with baseline.

RESULTS

A total of 133 patients underwent test stimulation with a 90% success rate, and 120 (110 females) of a mean age of 60.5 years and a mean duration of FI of 6.8 years received chronic implantation. Mean follow-up was 28 (range, 2.2-69.5) months. At 12 months, 83% of subjects achieved therapeutic success (95% confidence interval: 74%-90%; P < 0.0001), and 41% achieved 100% continence. Therapeutic success was 85% at 24 months. Incontinent episodes decreased from a mean of 9.4 per week at baseline to 1.9 at 12 months and 2.9 at 2 years. There were no reported unanticipated adverse device effects associated with InterStim Therapy.

CONCLUSION

Sacral nerve stimulation using InterStim Therapy is a safe and effective treatment for patients with FI.

Rectal motility after sacral nerve stimulation for faecal incontinence

Sacral nerve stimulation (SNS) is effective against faecal incontinence, but the mode of action is obscure. The aim of this study was to describe the effects of SNS on fasting and postprandial rectal motility. Sixteen patients, 14 women age 33-73 (mean 58), with faecal incontinence of various aetiologies were examined. Before and during SNS, rectal cross-sectional area (CSA) and ano-rectal pressures were determined with impedance planimetry and manometry for 1 h during fast and 1 h postprandially. Neither in the fasting state nor postprandially did SNS affect the number of single rectal contractions, total time with cyclic rectal contractions, the number of aborally and orally propagating contractions, the number of anal sampling reflexes or rectal wall tension during contractions. Postprandial changes in rectal tone were significantly reduced during SNS (P < 0.02). Before SNS, median rectal CSA was 2999 mm(2) (range: 1481-3822) during fast and 2697 mm(2) (range: 1227-3310) postprandially (P < 0.01). During SNS, median rectal CSA was 2990 mm(2) (1823-3678) during fast and 2547 mm(2) (1831-3468) postprandially (P = 0.22). SNS for faecal incontinence does not affect phasic rectal motility but it impairs postprandial changes in rectal tone.

A prospective, randomized study: switch off the sacral nerve stimulator during the night?

PURPOSE

Sacral nerve stimulation is an effective treatment for fecal incontinence. Some have recommended to "switch off" the pacemaker during the night to extend the lifetime of the expensive pacemaker. This study was designed to investigate whether a nightly "switch off" affects the clinical results of sacral nerve stimulation.

METHODS

Twenty patients successfully treated with sacral nerve stimulation (19 females; median age, 59 (range, 36-72) years) were randomized to: Group A, pacemaker continuously "on" for three weeks followed by three weeks with the pacemaker "off" during the night, or Group B, opposite order. Daily bowel-habit diary, Wexner, and St. Mark's incontinence scores were obtained.

RESULTS

One failed to return the daily bowel-habit diary, leaving 19 participating patients. Median Wexner incontinence score increased from 6 (range, 2-14) to 7 (range, 3-16) during the "off" period (P = 0.04), whereas St. Mark's incontinence score increased from 10 (range, 3-16) to 11 (range, 3-18; P = 0.03). Median number of days with soiling per three weeks increased from 0 (range, 0-12) to 1 (range, 0-15) during the "off" period (P = 0.008). Seven of 19 had more days with soiling during the "off" period. Defecation frequency per three weeks increased from 26 (range, 11-71) to 34 (range, 9-70) during the "off" period (P = 0.19). Only four continued with a nightly "switch off" after the study.

CONCLUSIONS

It could be considered to recommend compliant patients to "switch off" the pacemaker during the night to extend the lifetime of the pacemaker. One-third experienced increased soiling, and they should turn the pacemaker on all day and night. Among the remaining, only a minor proportion will be motivated for turning the pacemaker off.

Sacral nerve stimulation for faecal incontinence alters colorectal transport

Background

Sacral nerve stimulation reduces the frequency of defaecation in patients with faecal incontinence. The aim of this study was to examine the mechanism behind the reduced number of bowel movements in incontinent patients treated with sacral nerve stimulation.

Methods

The study included 20 patients with faecal incontinence and a positive percutaneous nerve evaluation test: 19 women and one man, with a median age of 63 (range 28–78) years. Colorectal scintigraphy was performed to assess colorectal emptying at defaecation before and after implantation. Segmental colorectal transit times were determined using radio-opaque markers.

Results

The median frequency of defaecation per 3 weeks decreased from 56 (range 19–136) to 26 (range 12–78) (P &lt; 0·002). At defaecation, antegrade transport from the ascending colon decreased from a median score of 8 (range 0–23) to 0 (range 0–11) per cent (P = 0·001), while retrograde transport from the descending colon increased from a median score of 0 (range 0–14) to 2 (range 0–30) per cent (P = 0·039). The median defaecation score was unchanged. There was a non-significant increase in median total gastrointestinal transit time from 2·5 (range 0·9–6·2) to 3·3 (range 0·8–6·2) days (P = 0·079).

Conclusion

Sacral nerve stimulation reduces antegrade transport from the ascending colon and increases retrograde transport from the descending colon at defaecation. This may prolong colonic transit time and increase the storage capacity of the colon.

Evolving therapy for fecal incontinence

BACKGROUND

Fecal incontinence is common and can be socially debilitating. Nonoperative management of fecal incontinence includes dietary modification, antidiarrheal medication, and biofeedback. The traditional surgical approach is sphincteroplasty if there is a defect of the external sphincter. Innovative treatment modalities have included sacral nerve stimulation, injectable implants, dynamic graciloplasty, and artificial bowel sphincter.

DISCUSSION

This review was designed to assess the various surgical options available for fecal incontinence and critically evaluate the evidence behind these procedures. The algorithm in the surgical treatment of fecal incontinence is shifting. Injectable therapy and sacral nerve stimulation are likely to be the mainstay in future treatment of moderate and severe fecal incontinence, respectively. Sphincteroplasty is limited to a small group of patients with isolated defect of the external sphincter. A stoma, although effective, can be avoided in most cases.

Sacral nerve stimulation for fecal disorders: evolution, current status, and future directions

Sacral nerve stimulation (SNS) aims to recruit residual function of the anorectal continence organ by electrostimulation of its peripheral nerve supply. Since its first application for the treatment of fecal incontinence in 1994, its acceptance has been broadened and it is today considered a valuable addition to the therapeutic armentarium. Initially, its use was based on conceptual considerations, but changed to a pragmatic trial and error approach. Thus, the patients selection evolved: patients suffering from fecal incontinence due to a wide variety of causes are today selected for permanent SNS after a phase of temporary test stimulation. This test is highly predictive. If it is of clinical benefit, a neurostimulation device is implanted for chronic stimulation. Permanent stimulation not only improves or restores continence, but also has a substantial impact on quality of life. This has been uniformaly proven in multiple single and multicentre trials in a wide variety of aetiologies causing fecal incontinence. Despite the growing experience with the clinical use of SNS and its therapeutic effectiveness, the knowledge of its mechanism of action remains limited. Current research aims to improve our understanding of its action, to expand the spectrum of clinical applications and to implement recent technical developments.

Rectal volume tolerability and anal pressures in patients with fecal incontinence treated with sacral nerve stimulation

PURPOSE

Sacral nerve stimulation has proven to be a promising treatment for fecal incontinence when conventional treatment modalities have failed. There have been several hypotheses concerning the mode of action of sacral nerve stimulation, but the mechanism is still unclear. This study was designed to evaluate the results of rectal volume tolerability, rectal pressure-volume curves, and anal pressures before and six months after permanent sacral nerve stimulation and to investigate the mode of action of sacral nerve stimulation.

METHODS

Twenty-nine patients with incontinence (male/female ratio = 6/23; median age, 58 (range, 29-79) years) underwent implantation of a permanent sacral electrode and neurostimulator after a positive percutaneous nerve evaluation test. Wexner incontinence score, rectal distention with thresholds for "first sensation," "desire to defecate," and "maximal tolerable volume," rectal pressure-volume curves, anal resting pressure, and maximum squeeze pressure were evaluated at baseline and at six months follow-up.

RESULTS

Median Wexner incontinence score decreased from 16 (range, 6-20) to 4 (range, 0-12; P < 0. 0001). Median "first sensation" increased from 43 (range, 16-230) ml to 62 (range, 4-186) ml (P = 0.1), median "desire to defecate" from 70 (range, 30-443) ml to 98 (range, 30-327) ml (P = 0.011), and median "maximal tolerable volume" from 130 (range, 68-667) ml to 166 (range, 74-578) ml (P = 0.031). Rectal pressure-volume curves showed a significant increase in rectal capacity (P < 0.0001). The anal resting pressure increased significantly from 31 (range, 0-109) cm H(2)O to 38 (range, 0-111) cm H(2)O (P = 0.045). No significant increase in maximum squeeze pressure was observed.

CONCLUSIONS

For patients with fecal incontinence successfully treated with sacral nerve stimulation, there was a significant increase in rectal volume tolerability and rectal capacity. A significant increase in anal resting pressure, but not in maximum squeeze pressure, was found. We suggest that sacral nerve stimulation causes neuromodulation at spinal level.

Sacral neuromodulation in the treatment of severe anal incontinence

INTRODUCTION

Sacral neuromodulation is a recognized therapeutic option in severe anal incontinence from neurogenic origins, when medical treatment has failed.

METHODS

We report the results of this procedure applied in 40 consecutive patients operated on by a single surgeon from August 2001 to June 2004. Mean duration of incontinence was 5 years. There were 33 women and 7 men of mean age 59 (range 29-89). All patients had had medical treatment, 26 had had physiotherapy and 9 had been previously operated on for that problem. Neuromodulation consisted in a temporary electrical stimulation test followed by implantation of a stimulator in case of efficacy.

RESULTS

Twenty nine patients had a positive test and were implanted. Ten had a negative test and one is waiting for implantation. From the 29 patients, 23 had uneventful postoperative course. Incontinence score varied from 17 before neuromodulation to 6 after in the 24 patients who were improved. Mean resting pressure, mean maximum squeeze pressure and mean duration of squeeze pressure did not change from pre to postoperative period.

CONCLUSION

Sacral neuromodulation is a safe and efficacious procedure in properly selected anal incontinent patients. However, we observed no correlation between clinical and manometric data.

Sacral neuromodulation; does it affect colonic transit time in patients with faecal incontinence?

OBJECTIVE

Sacral neuromodulation (SNM) has been a successful treatment in urinary voiding disorders for years. A concomitant effect on bowel function was observed leading to the treatment of faecal incontinence with SNM. In this study we describe the effect of SNM on bowel frequency and (segmental) colonic transit time.

PATIENTS AND METHODS

Fourteen patients with faecal incontinence who qualified for permanent SNM underwent a colon transit study before and one month after permanent implant. Patients completed a three-week bowel habits diary before and during stimulation.

RESULTS

Median incontinence episodes and days per week before SNM were, 8.7 and 4.2, respectively, and both decreased significantly to 0.67 (P = 0001) and 0.5 (P = 0001) during trial screening and to 0.33 (P = 0001) and 0.33 (P = 0001) after permanent implant. The median number of bowel movements per week decreased from 14.7 (6.7-41.7) to 10.0 (3.7-22.7)(P = 0005) during trial screening and to 10.0 (6.0-24.3)(P = 0008) during permanent stimulation. Resting and squeeze pressures did not change significantly during stimulation. Segmental colonic transit time before and during stimulation for right colon, left colon and recto sigmoid were, respectively, 6 (0-25) vs 5 (0-16) hours, 2 (0-29) vs 4 (0-45) hours and 7 (28) vs 8 (0-23) hours. No significant changes were found in both segmental and total colonic transit time; 17 (1-65) vs 25 (0-67) hours.

CONCLUSION

SNM in patients with fecal incontinence led to a significant decrease of bowel movements however (segmental) colonic transit time was not influenced.

Efficacy of sacral nerve stimulation for fecal incontinence: results of a multicenter double-blind crossover study

BACKGROUND AND AIMS

This is the first double-blind multicenter study examining the effectiveness of sacral nerve stimulation in a significant number of fecally incontinent patients.

METHODS

A total of 34 consecutive patients (31 women), median age 57 years (range, 33-73 years), underwent sacral nerve stimulation for fecal incontinence. After implantation, 27 of 34 patients were randomized in a double-blind crossover design to stimulation ON or OFF for 1-month periods. While still blinded, the patients chose the period of stimulation (ON or OFF) that they had preferred. The mode of stimulation corresponding to the selected period was continued for 3 months (final period). Outcome measures were frequency of fecal incontinence and urgency episodes, delay in postponing defecation, score severity, feeling of improvement, preference for ON or OFF, quality of life, and manometric measurements.

RESULTS

In the crossover portion of the study, the self-reported frequency of fecal incontinence episodes was significantly reduced during the ON versus the OFF period (P = 0.03), and this symptomatic improvement was consistent: 1) with the patients feeling of greater improvement during the ON versus OFF period (P = 0.02); 2) with the significant preference of patients (P = 0.02) for the ON versus OFF period. In the final period of the study, the frequency of fecal incontinence episodes decreased significantly (P = 0.005) in patients with the stimulator ON. The ability to postpone defecation (P = 0.01), the score for symptom severity (P = 0.0004), and the quality of life (P < 0.05) as well as anal sphincter function significantly improved.

CONCLUSIONS

The significant improvement in FI during the ON versus OFF period indicated that the clinical benefit of sacral nerve stimulation was not due to placebo.

Effect of sacral neuromodulation on the rectum

Background

Sacral neuromodulation (SNM) is a new treatment for faecal incontinence. At present the exact underlying mechanism is still unclear. Modulation of the sacral reflex arcs might have an effect on rectal sensitivity, wall tension and compliance.

Methods

Fifteen consecutive patients with faecal incontinence who qualified for SNM underwent barostat measurements before and during neuromodulation. An ‘infinitely’ compliant plastic bag with a volume of 600 ml was placed in the rectum and connected to a computer-controlled barostat system. An isobaric phasic distension protocol was used. Patients were asked to report rectal filling sensations: first sensation (FS), earliest urge to defaecate (EUD) and an irresistible, painful urge to defaecate (maximum tolerated volume; MTV). Rectal wall tension and compliance were calculated.

Results

During isobaric phasic distension each patient experienced all rectal filling sensations at the time of stimulation. Median volume thresholds decreased significantly during stimulation, from 98·1 to 44·2 ml for FS (P = 0·003), from 132·3 to 82·8 ml for EUD (P = 0·001) and from 205·8 to 162·8 ml for MTV (P = 0·002). Pressure thresholds tended to be lower for all filling sensations, but only that to evoke MTV was reduced significantly by stimulation (37·3 versus 30·3 mmHg; P = 0·005). Median rectal wall tension for all filling sensations decreased significantly with stimulation. There was no significant difference between compliance before and during stimulation.

Conclusion

SNM affects rectal sensory perception, but further research is required to clarify the mechanism.

Sacral nerve stimulation: an emerging treatment for faecal incontinence

Faecal incontinence is common, distressing to the patient and socially incapacitating. The treatment options depend on the severity and aetiology of incontinence. For mild cases of faecal incontinence, medical management and pelvic floor physiotherapy may be adequate. For more severe cases, surgery is often required. Patients who have a distinct sphincter defect are amenable to surgical repair. In many cases, there is a combination of diffuse structural damage of the anal sphincters with pudendal neuropathy. Conventional surgical repairs have a modest degree of success and the results tend to deteriorate with time. Neosphincter procedures such as artificial bowel sphincter and dynamic graciloplasty are potentially morbid and technically complex. Sacral nerve stimulation is innovative and has had a medium-term success with improvement of quality of life in over 80% of patients treated for faecal incontinence. These results are superior to other techniques in treating patients with severe refractory faecal incontinence, where current maximal therapy has failed. The technique is unique because there is a screening phase, which has a high predictive value. It is also associated with minimal complications that are usually minor. However, most published reports of sacral nerve stimulation for treatment of faecal incontinence were case studies and methods of assessing outcome were variable. Criteria for patient selection are evolving and are yet to be defined. The present paper critically reviews the publications to date on sacral nerve stimulation for treatment of faecal incontinence. This will form the basis for future evaluation of this emerging treatment of severe, intractable faecal incontinence. Randomized clinical trials like that of the Melbourne trial will further clarify the role and indications of sacral nerve stimulation for faecal incontinence.

Expanding indications for neuromodulation

Neuromodulation in one form or another has been studied for decades for various disease states. Although its mechanism of action remains un-explained, numerous clinical success stories suggest it is a therapy with efficacy and durability. Controlled studies have led to the approval of sacral neuromodulation for urinary urgency and frequency, urinary retention, and urinary urge incontinence. The future holds hopeful possibilities for the application of neuromodulation, namely in the areas of interstitial cystitis, in-tractable pain syndromes, fecal incontinence and constipation, spinal cord injury, and erectile dysfunction. Neuromodulators have also been used in nonurologic conditions, including chronic headaches and intractable chest pain. In adults and children, in the neurologically intact and neurologically impaired, neuromodulation has been shown to improve the quality of life of those suffering chronic disease states. Neuromodulation is changing the future of urology. Treatment of voiding dysfunction and likely other disorders, such as pelvic pain, sexual dysfunction, and bowel disorders, will no longer rely only on medications that are "OK" or destructive-reconstructive procedures that suffer from significant complications. Rather, by modulating the nerves, the urologists will treat these disorders in a minimally invasive fashion and neuromodulation will become the first-line therapy before any major surgery is undertaken.

Determination of therapeutic threshold in sacral nerve modulation for faecal incontinence

Background

The aim of the study was to determine the therapeutic stimulation threshold in patients with successful sacral nerve modulation for faecal incontinence.

Methods

Patients who had undergone successful permanent sacral nerve modulator implantation and had been followed up for a minimum of 3 months were included. The sensitivity threshold and motor threshold were determined and correlated with therapeutic response. Patients went home with the stimulator set at 0·6 V below the sensitivity threshold. Each week the voltage was increased by 0·2 V until the sensitivity threshold was reached. The effects on anorectal physiology and continence were recorded.

Results

Eight patients (seven women) with a median age of 58·5 years were included. The median follow-up was 6·3 months. The median sensibility threshold volume of rectal sensation was 50 ml, the median urge threshold volume was 140 ml and the median maximum tolerated rectal volume 240 ml. The median number of incontinence episodes and days per week affected by incontinence decreased from 5·0 and 3·8 before operation to 0·7 and 0·7 respectively after follow-up for 3 months. At anorectal manometry the median resting and stimulation anal canal pressures were 57 and 85 mmHg respectively, and remained constant over time. The therapeutic response threshold was significantly lower than the sensitivity threshold (median 1·6 versus 1·7 V; P = 0·042). The median motor threshold was 2·1 V, significantly higher than the sensitivity threshold (P = 0·009). The stimulation threshold for suboptimal therapeutic response was 1·4 V. In five of the eight patients the therapeutic response threshold was the same as the sensitivity threshold.

Conclusion

Sacral nerve modulation can produce a therapeutic effect below the sensitivity threshold. A lower stimulation voltage increases the lifespan of the pulse generator.

Innovations in fecal incontinence: sacral nerve stimulation

OBJECTIVE

The aim of this study was to present an overview of sacral nerve stimulation in the treatment of fecal incontinence. We describe the evolution in technique, patient selection, and indications, and review results and complications.

METHODS

All articles on sacral nerve stimulation for fecal incontinence that were recovered on MEDLINE search were reviewed. With multiple articles from an institution, the most recent reports with the longest follow-up and largest cohort of patients were selected, unless information from earlier reports was relevant.

RESULTS

The technique of sacral stimulation is well established, carries little risk, and continues to be refined (e.g., a less invasive approach has been proposed). Patient selection is based on a two-stage diagnostic test stimulation (acute and subchronic), for which the predictive value is high. On this basis, permanent sacral nerve stimulation has proved effective in both single-center and multicenter trials in patients with a functional deficit but limited morphologic lesions or no morphologic lesions. The clinical benefit derives from multiple symptomatic improvements contributing to better bowel control and from substantially improved quality of life. The underlying mechanism of action remains undefined, but both somatic and autonomic function appears affected.

CONCLUSION

Sacral nerve stimulation offers a safe treatment mode in a patient population in whom conservative treatment has failed and traditional surgical approaches would have limited success. The high predictive value of the diagnostic approach offers a unique therapeutic advantage.

Sacral neuromodulation for neurogenic bladder dysfunction in children

PURPOSE

We report a prospective randomized controlled study to evaluate the possible benefits of sacral neuromodulation (SNM) for the management of neurogenic bladder dysfunction in children.

MATERIALS AND METHODS

We included in the study subjects between the ages of 5 and 21 years presenting with urinary incontinence due to neurogenic bladder. Before study inclusion all previous treatment was discontinued. Patients were randomly divided into the control group treated conventionally and the implant group treated with SNM. Treatment outcome was compared every 3 months for a minimum of 12 months based on clinical examination, voiding diary and urodynamic evaluation.

RESULTS

A total of 26 boys and 16 girls with a mean age of 11.9 years were enrolled in this study. There were 21 patients in each group. The main underlying etiology was spina bifida. The 2 groups were comparable with regard to sex, age and urodynamic variables. Total disappearance of urinary leakage was observed in 1 patient who underwent implantation but he still required intermittent catheterization. Comparison of urodynamic variables disclosed no significant statistical difference except with regard to functional bladder capacity which was better in the control group and the leak point pressure which was better in the implant group (p <0.05). Evaluation of interindividual variations in the implant group revealed significant improvement in compliance and functional bladder capacity at 6 and 9 months but not at 12 months. Nine patients in the implant group reported improvement in intestinal transit, 5 total disappearance of urinary infection and 6 persistent sensation of a full bladder. No patient in the control group reported any improvement. Revision surgery was required in 3 cases due to lead migration, faulty connection and wound infection.

CONCLUSIONS

SNM is a promising new therapeutic modality. Implant placement is minimally invasive, nondestructive and reversible. Use in children with neurogenic bladder has not been previously reported. Although some improvement was noted in patients treated with SNM, the difference with the control group was not significant. A larger multicenter study is warranted to evaluate SNM.

Update on sacral neuromodulation: Indications and outcomes

Tanagho and Schmidt first introduced sacral nerve neuromodulation in 1981. Since then, it has become increasingly popular and the indications for this procedure are growing. The purpose of this article is to discuss the established indications for sacral nerve stimulation (SNS). The outcomes of the most recent studies and trials dealing with SNS are presented. An overview of the most recent techniques used for neuromodulation is detailed.